


Dennis Gaslights Mac

by Sunny_Bexster



Category: It's Always Sunny in Philadelphia
Genre: Canon Fatphobia, Dennis is a Bastard Man, Explicit Sexual Content, Fat Shaming, Gaslighting, M/M, Needy Dennis, Oral Sex, Season/Series 13, Sex, Sexually Competent Mac, Swearing, canon homophobia, codependent assholes
Language: English
Status: Completed
Published: 2020-03-17
Updated: 2020-03-17
Packaged: 2021-03-01 04:42:04
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,212
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23189422
Author URL: https://archiveofourown.org/users/Sunny_Bexster/pseuds/Sunny_Bexster
Summary: Dennis returns from North Dakota to a smaller, firmer Mac but he just can't resist trying to get inside his room-mate's head. Their fight starts the same as those that had gone before, but this has a very different ending.
Relationships: Mac McDonald/Dennis Reynolds
Comments: 3
Kudos: 61





	Dennis Gaslights Mac

Dennis had always intended his triumphant return to Philly to be an occasion. He was never the type to relay when and where he would be at any one time – he enjoyed being the element of surprise, appearing unannounced and putting his associates on the back foot.

That said, he could have easily guessed what he would see the second he walked back into the dingy South Philadelphia dive-bar - chaos. The four meandering, clod-brained idiots he'd left behind would fall even further into savagery without his leadership and sophistication. 

So imagine Dennis' surprise when he crossed that threshold, silent as a cat stalking through the night that he saw what the gang would, by their own admission, describe as decorum. There was no screaming, no arguments and insults being hurled across the bar top, no hazardous substances, no copious bleeding. Instead, the four morons he abandoned all those months ago, were listening with obvious patience and attention to Cindy.

The mouthy, ethnically diverse female posed no threat to Dennis and in hindsight, perhaps it was only right and proper the remaining gang had sought out another source of charisma, wit and power in his absence. 

Mac on the other hand had given Dennis a bit of a surprise, not least due to the hauntingly accurate sex doll propping up the bar. In his absence, Mac had changed and Dennis couldn't resist delivering a seemingly innocuous comment that he knew would torment Mac for hours, even days if delivered with the right level of indifference: “Hey Mac, did you gain a lil' weight?”

Right on queue, Mac had struggled to sputter out either a defence or an equally devastating comeback. Of course, he succeeded in neither and cast his eyes down to the bar top as the conversation rumbled on.

Only later on, as they entered their apartment did Dennis permit Mac a small bit of honesty and fondness.

“It's so good to have you back, man” said Mac, throwing his jacket onto the sofa.

“Well, it's good to be back” Dennis replied with a small, thin smile which his room-mate returned with incredible warmth. “Just in the knick of time too” he continued “Now I'm back I can help you work off those pesky couple of pounds that have crept on whilst I've been away...”

“What?” Mac glanced down at his torso, gently flexing his arms “No, no – this is mass. I've gained mass”

Dennis all but sighed “Mac, you need to stop using that word. You evidently don't know what it means as you have not gained mass.”

“No, y'see – look” Mac turned his torso to the left, tightening his shoulders and bending his elbows to pronounce the curve of his triceps. “This is like...all muscle. Mass, dude. I got mass”.

His explanation was met with a shrug. Dennis watched, half fascinated and amused as Mac continued showing off body parts.

“Oh c'mon, man” he pulled up the hem of his t-shirt, revealing an impressively taut lower stomach and, even more amazingly, side abs. As Mac pulled his t-shirt higher, Dennis was treated to a show of a fairly formidable six-pack - a sight he would never have expected to see on Mac, whose body type had alternated between lazy twink and lazy fatso.

“I could shred cheese on these abs, man – I'm tellin' you”

“And it's clear to me that what you're doing after shredding said cheese...is eating it, Mac. Eating all of it.” replied Dennis, his tone cool and flippant “face it – you gained a little weight whilst I was gone, it's fine. We're all getting older” he paused and scoffed lightly “well, not me but you catch my drift.”

Mac was now getting irritated. “Look, you're not getting the full picture” the t-shirt was unceremoniously tugged over his head and discarded. He flexed and preened at Dennis, turning his torso left and right, twitching and clenching various muscles all the while searching for that validation he so desperately craved. 

“I've obviously hit a nerve” said Dennis, perching on the arm of the sofa, watching Mac perform his one-man Mr Universe routine. “Put your shirt back on and just...just forget I ever mentioned anything.”

“Wait, no – it's the light. That's gotta be it. Lemme just-” Mac took a few steps back towards the kitchen, striking a pose under what he considered to be a more flattering pool of light. “Better? Dennis...is that better? Can you see my mass now? Do you see how...how ripped I am?”

The spectacle had gone on long enough. Dennis needed to deploy his last hail-Mary to soothe a highly-strung Mac. It was a look – a slight downturn in the mouth, a furrowed brow, topped off with a pair of crossed arms. The argument killer. Ender of tantrums. Destroyer of confidence. 

Mac, who had been subject to that look many times before knew he was defeated. He let his arms drop to his side, crestfallen“I...I shoulda cut this week. That's what I shoulda done – I did my bulking cycle last week and I was gonna cut but there was the whole...'Make Paddy's Great Again’ plan and...” he trailed off, biting his lower lip in disappointment. 

Dennis left the arm of the sofa and approached the shirtless dejected man. “Mac” he said softly “Whatever you're doing...it's not working” he gestured up and down Mac's body.

A small ripple of anger washed over Mac. First, his efforts were wasted on whatever plan Cindy had come up with – he was convinced there could have been a place in that plan for his rocking bod. And then, Dennis comes back, stirring up all the hope and hurt that that brings...only for him to dismiss all of Mac's efforts, to sneer at all of his hard work and sculpted muscles.

“So, you think I'm fat – yeah?” it was a demand, rather than a question.

“Absolutely” replied Dennis, with zero hesitation. The space between him and Mac was rapidly closing. With each step he took towards the bearded man, Dennis noted the definition, the way Mac's skin was stretched across pectorals and abdominals.

“Really fat?” again, Mac's tone was sharp as he stared at Dennis with intense, unblinking scrutiny. 

“Yes. Really...really fat”

They were almost upon each other now. Inches apart, Dennis swallowed slightly as he was close enough to drink in every aspect of Mac's new body.

“Well, doesn't that just suck?” sighed Mac with heavy-handed sarcasm “Cos, I guess no dude is going to want to sleep with me...the fatty” he gestured to his torso, which he knew carried less than 10% body fat.

“Not unless he's into Bears, Mac” muttered Dennis, whose finger tips reached out to gently trace the curves and dips of Mac's stomach.

For a few seconds, the pair was still – Dennis lost in the tactile experience of Mac's muscles, his willpower beaten and crippled by feelings he'd not yet been aware of until today. Mac on the other hand was paralysed by nerves and excitement. 

He briefly wondered if he'd dropped unconscious at some point - was this another horny nightmare? Dennis, gliding his slim fingers across his aching body all whilst ripping the shit out of his efforts and looks had all the telltale signs of an erection-inducing nightmare.

Dennis raised his head, meeting Mac's expectant gaze. The silence crackled between them, as Dennis flattened his palm against his room-mate's stomach, before sliding his hand upwards to Mac's chest, relishing the feel of the frantic heartbeat beneath. By this point, the quiet within the apartment was roaring in both of their ears. They stared at each other, neither one sure of what to do.

It was Mac who shattered the stillness that had built up, his voice small and cautious “I really missed you, Dennis”

Dennis threw himself forwards with an almost primal grunt, wrapping his arms around Mac's neck and pressing his hips hard against Mac's crotch. With a small flutter of excitement, Dennis noticed how Mac hadn't budged when Dennis had flung himself towards. Maybe Mac was right – maybe he had built up some mass.

As shocked as Mac was at this display of affection and amorousness from Dennis, he wasted no time in reciprocating – he kissed Dennis deeply, something he'd been yearning to do for...decades, honestly. His fingers fumbled with the fiddly buttons of Dennis' shirt, growing increasingly irked before he simply rips the garment open. Dennis was pale, no doubt due to the North Dakota winter. 

Mac allowed his hands to wander across the back of Dennis' body, clutching at his shoulders, hips, that amazing ass before finally grabbing his thighs and hoisting him upwards. Dennis moaned into the kiss, wrapping his legs around Mac's waist, reeling from the way he was being carried like he weighed next to nothing.

With almost dogged determination, their kiss remained unbroken as Mac walked towards the kitchen, resting Dennis on the edge of the kitchen sink but not before rolling his hips against him, letting him feel the solid slab of buffness his body had become. 

At some point, they both needed to come up for air. They broke apart, breathing heavily as they sized each other up, wondering who will be the next one to initiate. Mac peeled Dennis' now ruined shirt off his shoulders, leaving it pooled around his hips which he couldn’t resist dragging his fingertips across.

Dennis slides himself down off the sink edge, his breath hitching at the feel of Mac's strong hands following his thighs downwards. He stops, balancing on tiptoes, a small wet patch growing on his shirt from the damp sink edge. He feels off-kilter, dizzy and hungry for more touches. 

Mac smiles; he does that damnable lopsided grin that tugs at something hidden deep in Dennis' chest. Caught up in the madness of it, Dennis smiles back and can barely contain the gasp that escapes his lips as Mac goes down to his knees. With surprising tenderness, Mac undoes Dennis' belt and jeans, gently tugging the waistband downwards.

What followed was nothing short of mind-blowing. Through drunken calls and voice-mails, Dennis had found out about Mac's exuberant embrace of the gay sex scene. At least once a week, Dee would phone her brother solely to whine, rant and vent at him in a state of near blackout drunkenness. “Aaannnd Mac's jus'...jus' being a gay, big ol' gay man slut so...yeah...an' he just brings in all this...this” at this point in the sentence there was usually a belch and the sound of her swigging something that was definitely 70% proof “glit....glitter into the bar an' its g-glitter from all the...gay man slut sex...”. 

Dennis hadn't entirely been celibate whilst in North Dakota – a man of his needs could never stand to be...but as Mac's lips touch the sensitive tip of his dick, he wondered how he'd ever lived without that feeling that sensation. Years lost.

He gasped, unable to contain his reaction this time, as Mac worked through a play-book of knee weakening blow-job techniques, each one performed with a gusto that only 40 years of sexual repression can bring. Dennis was already feeling unsteady on his feet, drunk on the pace and ferocity of their caressing, but with every lick or suck he felt the world tumbling a little quicker.

Mac must have clocked the precariousness of Dennis' position; he reached up to hold onto his room-mate's hips and guided him downwards with a smile. Using his newly toned arms, he lowered Dennis onto the floor, taking care to ensure the little mat in the kitchen provided a barrier between them and the cold of the tiles, before continuing to deliver an award-worthy blow-job. 

Dennis feels he’s in danger of losing any sort of control over this situation. Whilst the immense pleasure he’s receiving from the attentions of his room-mate is giving him the smallest hint of hope for happiness that is more than fleeting, it’s also making him feel exposed and vulnerable.

“I bet” he pants, his hips bucking as Mac does something especially complicated with his tongue “I bet if I opened that fridge right now, it’d...it’d be just full of junk food...really, really unhealthy shit”

Without a pause, Mac reaches behind him, grabbling for the refrigerator handle which he yanks open for Dennis’ inspection.

“Y’see” says Dennis, trying to focus on the contents when all he wants to do is close his eyes and be swept away in the sensations he’s feeling “Unhealthy shit like....bottled water...turkey mince and-and...green stuff….holy shit, it’s freshhhhh” his voice raises several octaves as Mac raises his head to grin at Dennis but not before delivering a parting flourish. He kicks the refrigerator door shut and crawls up Dennis’ body, to set about preventing any further snarky comments about his diet.

Like a couple of teenagers at a house party, the pair exchanged a series of frantic, messy kisses as they thrashed around on the kitchen floor. By now, Dennis had dispensed with gentle touches and caresses; he found himself clawing at Mac's flesh, clasping at his arms, back and ass desperate to feel every inch of this new body. 

Emboldened by Dennis' frenzied affections, Mac felt out for his room-mate's hand, pausing briefly to enjoy the warmth and softness of those long, slim digits as they interlocked with his. He pushed Dennis' hand down to feel his erection that was straining painfully against the crotch of his pants. 

With a barely audible moan, Dennis lightly pushed Mac away and the pair spent several seconds panting from their exertions. “Bedroom” he gasped, scrabbling to get his footing. His legs were entangled with Mac's, the weight of his thighs making him feel small and light all over again.

Mac was on his feet quicker than Dennis, his desire for sex no less intense despite him trying to fuck half of Philadelphia's gay men since accepting his sexuality. He held out his hands, helping Dennis as he stood up with none of his usual grace or speed.

The pull of the other was too great; Mac and Dennis found themselves interlinked once more, each one intent on exploring the other's body as quickly but as comprehensively as possible. Mac again grabbed the back of Dennis' thighs, lifting him up and feeling a completeness of those same legs wrapped around him. 

Mac kissed the length of Dennis' neck as they left the kitchen – all decorum was lost now, as he moaned, helpless and needy, enveloped in the arms of this new confident and out Mac.

The trip to the bedroom was awkward, with urgency and the distraction of Dennis' kisses causing Mac to ricochet off door frames, sofas and tables. Without thinking, he headed towards Dennis' room, determined to be his next conquest like the scores of women that had come before. 

Whilst Dennis had been in North Dakota, Mac had needed to keep Dennis' door shut, trying to block out the reminder that the man he wanted nothing more than to be there was half the country away. The door was currently closed. 

“Lemme” muttered Dennis, reaching out behind him to grab the handle but before he had a chance, Mac delivered a single precise and devastating kick to the door, which flung open. The greatest kick of his lifetime, but which paled in significance for what he was waiting for. 

“That felt unnecessary” said Dennis, turning back to look at Mac.

“Felt super cool and hot to me, man” said Mac, stepping across the threshold and throwing Dennis onto the perfectly made bed, before jumping on after him.

The pair writhed around, trying to keep their momentum whilst kissing and struggling to extract legs out of pants. Eventually, both were naked on top of the covers, breathing heavily. Dennis was shown the full phenomenon that was Mac’s body, stretched out across his bed and ready to be taken.

“Actually” smirked Dennis, leaning across Mac’s chest to extract a condom from the drawer of his nightstand “you look good with a little weight...”

“You dick” laughed Mac.

For two people who had never slept with each other before, Mac and Dennis moved with each other like they were performing an old, much treasured dance. There were no arguments about power bottoms or who deserved to top; instead their movements were fluid and in sync, eager to please and be pleased.

They continued in their rhythm, the momentum growing with each passing second and serenaded by the creaking of the bed frame. Dennis pushed hard against Mac, breathless and hot but hyper aware of every touch, every sensation. In that time, nothing else existed - all that mattered was the way this felt. He was craving the climax but part of him never wanted this experience to end.

Dennis couldn’t help but yelp in surprise as Mac rolled him over, holding him between those strong thighs. By this point, their movements had become rapid and intense, the heat and the noise in the room increasing towards a dramatic, blissful end. Neither one was holding back now - they were two naked, eager, hungry bodies intent on stealing a slice of happiness from each other and the world. 

Naturally, this was the point at which Dennis’ bed broke.

There was a crack and one mattress tipped towards the floor, throwing the pair off balance and bringing the event to a halt with an almost audible screech.

“oh shit, dude” said Mac, peering over the mattress edge to see what the damage was “I think we broke your bed”

Dennis laughed. It was one of his rare, genuine laughs - it wasn’t derisory or meant to hurt. It was warm and heartfelt. The absurdity of the situation had amused Dennis - months exiled in North Dakota and within hours of him being back and Mac had given him a broken bed and what was shaping up to be a stupefying orgasm.

Undeterred, they finished and revelled in just lying next to each other, gazing up at the ceiling fan and breathing heavily - exhausted but satisfied.

“Well, that burned a few calories” said Mac, making Dennis laugh and mean it twice in one day.

The small space they’d built for themselves was never going to stay uninterrupted for long. The rest of the gang descended on their apartment later than night, armed with questionable movies and cheap beer. Dennis and Mac dropped back into the roles they’d gotten so used to playing - roommates, alleged friends and frequent fighters. 

“Oh shit, man what happened to your bed?” asked Charlie, pointing to the lopsided furniture, its covers still unmade from Mac and Dennis’ afternoon activities.

“What? Oh that.” replied Dennis, feigning indifference as he carried a bowl of popcorn from the kitchen. He caught Mac’s gaze as he set the bowl down on the coffee table and gave him a small, cheeky smile “Mac broke it with his fat ass”.

As Dennis listened to the rest of the gang tease the ever-loving shit out of Mac, no doubt with a few ideas as to how the bed broke, he sighed contentedly and hoped that the bed-frame on Mac’s bed was made of stronger stuff.


End file.
